# The Freezing Point of 80 Proof Whiskey

#### 29 SEP 2017

#### CLASS

In February 2010, explorers in the Antarctic happened upon a post abandoned by the Shackleton expedition in 1910. One of the most unusual discoveries was several unopened cases of 80-proof whiskey and brandy that were left behind and buried in the ice. The whiskey was still in liquid form, and here's why.

## 1 Pure Ethanol

The alcohol formed in beverages such as whiskey and brandy is called ethanol, and this liquid freezes at 114 degrees below zero on the Celsius scale. However, alcohol spirits are never that pure, so the freezing point of a whiskey is largely dependent on the percentage of alcohol it contains. The proof system is a very straightforward manner of measuring alcohol content -- the numerical value expressed by proof is exactly twice the actual alcohol content. Therefore, 80-proof whiskey would contain 40 percent alcohol.

## 2 Freezing Point Calculations

In whiskey and other hard liquors, 40 ml of alcohol can be dissolved in 100 ml of water to create the 80 proof or 40 percent mixture. However, the freezing points of the different proofs of alcohol are actually affected by something called molality. Molality is determined by comparing the molecular weights of the two liquids and determining a ratio, which is then mathematically applied to the temperatures of each substance.

## 3 Final Result

After all calculations are said and done, the freezing point of 80-proof alcohol is -26 Celsius or -16 Fahrenheit. These are reachable air temperatures in Antarctica, so the aforementioned alcohol might have frozen if left in the open air. But this alcohol was embedded in ice and as such remained closer to the freezing mark.